一类活性Petri网控制器的冗余检测及结构简化  

Redundancy detection and structure simplification for a class of liveness-enforcing Petri net supervisors

作　　者：徐姗姗[1] 董利达[2] 朱丹[3] 朱承丞[3] 

机构地区：[1]解放军陆军军官学院管理工程教研室,安徽合肥230031 [2]杭州师范大学杭州国际服务工程学院,浙江杭州310012 [3]浙江大学电子电路与信息系统研究所,浙江杭州310027

出　　处：《控制理论与应用》2013年第6期673-682,共10页Control Theory & Applications

基　　金：国家自然科学基金资助项目(61071062);浙江省自然科学基金资助项日(Y12F02030)

摘　　要：S^4R(systems of sequential systems with shared resources)网是分析和解决柔性制造系统死锁现象常用的一种重要的Petri网子类模型,现有的基于S^4R网的死锁预防方法通常采用对部分或者全部严格极小信标添加控制库所来实现.此类方法的不足在于得到的活性S^4R控制器中往往存在冗余控制库所.针对已为网中每一个严格极小信标都逐一添加了控制库所和相关连接弧的活性S^4R控制器,本文提出并设计了一种基于整数规划技术的冗余检测及结构简化方法,由此得到结构更简单、行为允许度更高的活性S^4R控制器.该方法的核心思想是:如果网中已经存在一个P-不变式使得某个严格极小信标满足最大受控条件,那么为该严格极小信标添加的控制库所就是冗余的.由于该方法无需进行Petri网的可达性分析,避免了状态组合爆炸问题,因此具有较高的可行性和计算效率.最后用实验验证了本文方法的正确性和有效性.S4R （systems of sequential systems with shared resources） is an important subclass of Petri nets used in ana- lyzing and solving deadlock problem of flexible manufacturing systems （FMS）. Control places and related arcs are usually added for all or some of the strictly minimal siphons （SMS） by the existing S4R-oriented deadlock prevention methods. The defect of such methods is that there are redundant control places in the generated liveness-enforcing supervisors. For a liveness-enforcing S4R supervisor in which each SMS has been controlled by its control place, this paper proposes an integer-programming-technique-based method to detect the redundancy for control places and simplify the structure for the system. Then, it can produce the liveness-enforcing S4R supervisor with simpler structure and more permissible behaviors. The main idea is that if there is already a P-invariant in the net which makes an SMS max-controlled, then the control place added for this SMS is redundant. Because this method doesn＇t need the reachability analysis, it can avoid the state explosion problem, and therefore it brings about high feasibility and computational efficiency. Finally, the experiments validate the correctness and feasibility of the proposed method.

关 键 词：PETRI网 柔性制造系统 信标 死锁预防 整数规划 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]